In commercial buildings and various other venues, there is a need to provide emergency lighting in the event of a mains (i.e., main power supply) power outage. Mains electricity is the electrical power supplied via mains power systems (such as power grids) found throughout the world to, among other things, homes and businesses. An interruption of mains power, commonly referred to as a mains power outage, includes brownouts (e.g., a reduction in or restriction on the availability of electrical power in a particular area) and blackouts (e.g., a total loss of power to an area). Regulations in many areas of the world require that emergency lighting systems in, for example, commercial buildings maintain a minimum level (lux) of light for a minimum amount of time to allow people to safely exit the building in the event of mains power outage. The regulations may also require that the emergency lighting system(s) are tested periodically to ensure compliance with the emergency lighting requirements. Conducting periodic tests to ensure that emergency lighting systems continue to meet regulatory requirements is especially important as lighting systems increasingly incorporate light emitting diodes (LED) as light sources, because LEDs tend to not fail suddenly and completely as with some other light sources. Rather, the luminosity of an LED tends to slowly degrade over time, which may lead to a more subtle dip below the required amount of light emitted by the LED.
Exemplary known emergency lighting systems include maintained and non-maintained battery backup fixtures. A maintained fixture is a fixture that is, or may be, illuminated all the time. The maintained fixture switches to an emergency fixture if the unswitched mains feed has no power and also includes a switched feed to control the light (i.e., turn it off) without switching the light to emergency mode. A non-maintained fixture is a fixture that is only illuminated during a mains power outage when there is no power from an unswitched feed. A fixture of either type requires a constant live electrical feed to keep the battery backup power source charged. The battery backup may be a centralized battery system which replaces the mains feed to the lighting fixture circuit(s) in the event of a mains power loss.
Many typical, known test procedures for emergency lighting systems are manual and require, e.g., a maintenance engineer to physically cut the mains power to the lighting system to allow the battery (or other) backup power supply to power the emergency fixtures. The maintenance engineer must then ensure that the fixtures maintain the required amount of light for the required amount of time. Such a manual method is laborious, time consuming, and costly. Digital Addressable Lighting Interface (DALI®) protocol is a known, standard lighting protocol including emergency testing protocol(s) that may reduce the time and cost of the testing procedure. For example, the test procedure may be initiated according to a schedule or manually at a control panel. However, a maintenance engineer must nonetheless be present to observe the testing procedure and results. Further, in countries such as the United Kingdom (UK), the emergency lighting has to perform with minimum lux levels for a certain amount of time, e.g., three hours, at which time the test is completed and the results of the test are simply pass/fail based on visual confirmation from the maintenance engineer that the required amount of light was maintained for the required amount of time. Typical emergency lighting tests may include, for instance, a monthly visit to cut the power to the mains unswitched power supply to each circuit, check all the emergency lights and sign a register that the test was carried out and all emergency lights were ok. Then the same test would be carried out annually but the engineer would have to wait during the test period (e.g., three hours in the UK) and file a report stating all emergency lights were still lit at the end of the time period.
There are many standalone self-test emergency systems which utilize the DALI® protocol that have built in emergency test functionality, with a centralized emergency monitoring system to replace the physical switching to be automated/centrally instigated. Known lighting systems may include a “smart emergency system,” e.g., a system having a DALI® set up and capable of two-way communications with a user or control system. For example, DALI® commands may initiate an emergency test by switching a light source to battery backup power and then report back information such as test complete for 3 hours, etc., over DALI®. The DALI® protocol can also report back to the central system information about the batteries and drivers, i.e. number of switching cycles, how many times the batteries have been discharged, if the power to the fixture lasted the correct amount of time (as a yes/no output). Such systems are typically expensive to install, lack dynamic integration with the lighting systems and devices in the building, do not provide remote control, and do not offer any predictive emergency analytics. Those systems are configured based on the present conditions and components during initialization and cannot adapt to changes regarding lighting devices, environments, and/or requirements. In addition, such systems can only offer estimations of failure based on the number of switching cycles, discharge cycles and warranty/expected lifetime usage information, e.g., from a manufacturer. Further, many of these systems nonetheless require a person to be present to verify that the emergency lights function as required.
With respect now to FIG. 1, a known maintained luminaire fixture 10 is shown including, among other things, a fixture that is normally in use (illuminated) and can be switched via the switched supply (and dimmed if it includes a dimmable driver). As shown in FIG. 1, an emergency module 15 and battery supply 20 are switchably connected to an LED light fitting 30 with an unswitched live supply 50 of power for normal operation. The fixture 10 must have a charge indicator LED 40 that is located below a ceiling or other structure in which the fixture 10 is installed and visible to users. The charge indicator LED 40 indicates whether the battery is connected and charged. Other components of the fixture 10 may be above or within the ceiling or structure in which the system is installed, or elsewhere.
The fixture 10 shown in FIG. 1 may be connected to an overall lighting system in typically two ways. First, if the fixture 10 is non-dimmable or dimmable according to a 1-10V protocol (i.e., needs a relay to cut power to turn it off) it has 2 gateways. One gateway is connected to a switched supply 60 of power to handle the on/off switching and/or dimming. The second gateway is connected to the unswitched live supply 50 to handle cutting the power to simulate power loss for testing.
With reference now to FIG. 2, a known non-maintained luminaire fixture 10′ that is normally off is shown including, among other things, a single mains feed 50′ (not switched) such as a 240V power supply to an emergency module 15′ including a connection 20′ to a battery supply. The fixture under battery power kicks in if the mains feed 50′ is lost. The fixture 10′ must also have a charge indicator LED (not shown) that is located below a ceiling or other structure in which the fixture 10′ is installed and visible to users. The charge indicator LED indicates whether the battery is connected and charged. Other components of the fixture 10′ may be above or within the ceiling or structure in which the system is installed, or elsewhere. The non-maintained fixture 10′ shown in FIG. 2 does not include a dimming function as the fixture 10′ is only illuminated in an emergency, therefore a simplified gateway without a dimming control, such as shown in FIG. 3, would be sufficient to control the fixture 10′ shown in FIG. 2.
Accordingly, there is a need for emergency lighting systems having automated self-test capability including predictive analytics on the emergency lights. There is also a need for such systems to dynamically integrate with overall lighting systems including, e.g., maintained, non-maintained, and smart emergency systems having different, replaceable, and/or reconfigurable components and operations.